[PATCH 1/1] um: virt-pci: Switch to msi_create_parent_irq_domain()

[Johannes Berg]

On Fri, 2025-06-27 at 10:49 +0200, Nam Cao wrote:
> 
> Thanks for testing! The later kernel crash should be fixed with:
> 
> diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c
> index e51a9357934da..557d93aea00a1 100644
> --- a/arch/um/drivers/virt-pci.c
> +++ b/arch/um/drivers/virt-pci.c
> @@ -407,7 +407,6 @@ static const struct irq_domain_ops um_pci_inner_domain_ops = {
>  
>  #define UM_PCI_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS		| \
>  				   MSI_FLAG_USE_DEF_CHIP_OPS		| \
> -				   MSI_FLAG_PCI_MSI_MASK_PARENT		| \
>  				   MSI_FLAG_NO_AFFINITY)

Can confirm that.

> I have no immediate idea about the lockdep warn, I don't see how the
> MSI_FLAG_PCI_MSI_MASK_PARENT flag can be related to that. Probably there's
> another problem, let me stare at it..

Seems to go away as well, perhaps it's due to taking some wrong path
with the flag just prior to the crash?

IOW, works for me with the above change with no crash and no lockdep
warning either.

johannes